EX600- smaller version of HT1250 - intermittent receiver

[g8tzl2004]

I have just acquired a UHF EX600 ( GP388 / GP338Plus) - this is the "smaller" version of the HT1250.

After programming the radio, I set the radio scanning today and it initially appeared to be working OK. I then left the EX600 for a couple of hours. When I then checked the radio again it did NOT appear to be receiving. I got the following issues:

- when I opened the squelch, the white noise did NOT sound 100% correct - you could still hear the hiss but it did not seem quite right.

- when I tried a low level test signal from another radio, you could only hear the same hiss rather than a modulated carrier but there was a bit of a "clunk" noise when you pressed the PTT but mainly all you received was hiss. However, when you shouted into the mic on the other radio, you could hear splatter on the EX600...when you talked at normal levels. all you could hear was the same hiss. It was like the EX600 was RXing but NOT on the intended frequency!!

- the TX side of the EX600 continued to work 100%

- I switched off the EX600 and after 15 minutes I powered it up. The RX side was working again and has continued to work for a couple of hours.

Any thoughts? Before I noticed that the EX600 receiver was not working, the low battery alert had been sounding. I immediately swapped the battery but the receiver side was still not working. Maybe its a VCO or IF/Mixer issue? Maybe the 2nd LO IF Xtal was off freq for some reason (faulty/lazy Xtal or leaky cap?)

Thanks

[g8tzl2004]

The RX intermittent happened again with a fully charged battery. I was out and about and somebody was calling me and I was hearing nothing.

When I opened the squelch I was getting slightly distorted white noise together with a very low level whistle. When I pressed the PTT a few times , the normal white noise came back and I was receiving again.

Any ideas?

I think I have seen this with one of my Jedi's - mixer/IF problem I think - maybe dry solder joint on uBGA chip?

[CircleBat]

Common problem with these radios.. either the ASFIC chip or the filters are gone.. really hafta trouble shoot these radios.. not a easy radio to repair

CircleBat